Which U.S. cell phone service is the best when it comes to what you really use a phone for these days -- data? Which gives you the most widespread and reliable access to its data network, fast upload and download speeds, the most bang for your buck?

We set out to discover all that, and more, by turning to the experts -- you and other Computerworld readers. We conducted a six-week-long online survey asking smartphone users to rate their mobile Internet service provider in a variety of categories: average upload speeds, average download speeds, availability of connection, reliability of connection, performance relative to cost, technical support, selection of phone models and customer service/billing.

For each category, respondents were given five choices: very satisfied, satisfied, neither satisfied nor dissatisfied, dissatisfied and very dissatisfied. We tallied the results from our 820 respondents and came up with the winners ... and the losers.

The vast majority of our survey respondents, 93%, use one of the "big four" U.S. cellular service carriers: 37% use Verizon Wireless, 32% use AT&T, 14% use Sprint and 10% use T-Mobile, and those are the providers we've rated in this story. We did, however, include all survey responses when discussing overall satisfaction results, mobile data use and other general statistics.

We asked other questions as well, about how often people use mobile data networks and for what, why they chose their mobile service provider, how much they pay monthly and more. Based on all the results, we've come up with a snapshot of mobile data use and satisfaction today.

We found, for example, that contrary to what you might think, people are generally satisfied with their data networks, with two-thirds saying they were either satisfied or very satisfied. We also found that only about a third of respondents use a mobile data network to stay connected via social media, and network coverage was the main reason people chose their current carrier.

We've discovered a lot more as well. Read on to find it all out.

What you think about mobile data service

Before we take an in-depth look at the winners and losers for mobile data service providers, let's see how, as a group, they rated with customers. From all the griping people like to do about mobile service providers, you'd expect that few users are really happy with them -- but people on the whole gave them solidly good ratings.

Editor's note: For the sake of readability, in the story text below we've combined the "very satisfied" and "satisfied" responses into a single "satisfied" percentage, and we've likewise combined the "dissatisfied" and "very dissatisfied" responses into a single "dissatisfied" percentage. The accompanying charts show the full percentage breakdowns.

Data connection availability and reliability

Let's start off with the basics: Are people satisfied with their data connection being there when they want it? In other words, how happy are they with the network coverage and availability -- can they get online wherever and whenever they want to?

The answer: Generally, yes. A full two thirds, 67%, said they were satisfied. Only 17% were dissatisfied.

But that varied greatly by carrier, with 77% of Verizon customers saying they were satisfied. At the other end of the spectrum, only 48% of Sprint customers reported themselves as satisfied, and more than a third of Sprint customers, 36%, said they were dissatisfied.

People are almost as pleased with the reliability of the connection (once they're connected, do they stay connected?) as its availability. Some 61% reported themselves as being satisfied. Less than a quarter, 18%, said they were dissatisfied.

Once again, Verizon was tops, with 70% saying they were satisfied and only 12% dissatisfied. T-Mobile and Sprint rated the worst. Only 44% of T-Mobile customers reported themselves as satisfied, and almost a quarter, 24%, said they were dissatisfied with T-Mobile's network reliability. Sprint fared no better, with 46% of its customers reporting themselves as satisfied and 36% saying they were dissatisfied.

Download and upload speeds

People are just as happy with their provider's data download and upload speeds as with the availability and reliability of the connection.

Some 66% said they were satisfied with the average download speed. Only 16% were dissatisfied.

Verizon once again was the top performer, with 71% satisfied and just 9% dissatisfied. Sprint was the worst, at 49% satisfied and 38% dissatisfied.

Customers are not quite as pleased with upload speeds, with 59% satisfied; on the other hand, only 14% said they were dissatisfied.

Can you guess the winner and loser? Yes, you can. Verizon was tops again with 64% satisfied and only 9% dissatisfied. And fewer than half of Sprint users, 44%, were satisfied with upload speeds. Some 32% of them were dissatisfied.

Value and phone selection

A high-performing network is one thing, but bang for the buck is something else entirely. So we asked customers what they felt about the data network performance of their providers compared to what they're paying.

As a whole, they're only moderately pleased, with 52% saying they were satisfied and 25% saying they were dissatisfied.

It's clear that the smartphone wars are good for consumers, because they reported themselves as being extremely pleased with the selection of available phones from their carriers -- a whopping 81% said they were satisfied, and only about 6% were dissatisfied.

AT&T won by a mile here, with 90% of customers satisfied and only 2% dissatisfied. Even customers of T-Mobile, which rated the worst in this category, are still a happy bunch, with 70% satisfied and 12% dissatisfied.

Tech support and customer service

We've all been there: Stuck on hold listening to easy-listening music that is not so easy to listen to, fuming while we wait our turn to get non-answers to even the simplest of questions.

Or maybe not. At least, that's what our findings show. People are reasonably pleased with both the technical support and the customer service that their cell phone providers offer.

For technical support, about 58% of people said they were satisfied, and only 9% were dissatisfied. T-Mobile came out on top here, with 68% satisfied and only 9% dissatisfied.

People are even more pleased with the customer service they get, with 65% being satisfied and 11% dissatisfied on average.

There were no great differences among cell providers when it comes to customer service satisfaction, but for once, Sprint topped the bunch in satisfied responses, at 68%. However, Sprint also had the highest rate of dissatisfied responses at 14%. AT&T's 63% satisfied responses were the lowest in the bunch, with 11% of AT&T customers saying they were dissatisfied with its customer service.

Your mobile data use

How do people actually use their mobile data? Are they on 3G or 4G networks? What are their primary uses for the network once they hop on? The survey has some interesting and definitive answers to these and other questions.

People are transitioning to high-speed 4G networks, with 4G slightly ahead of 3G. Some 39% said they connect via 4G networks, 32% via 3G and 26% on either 3G or 4G, depending on their location. The remainder of people either don't know what speed network they use, or else are using a 2G network.

T-Mobile users are 4G-centric, with 57% reporting that they always connect via 4G, while Sprint users are slowpokes, with only 11% always connecting via 4G.

Somewhat surprisingly, our survey shows that smartphone users are not data addicts -- at least not when they're connecting via a mobile network instead of Wi-Fi. Only 31% reported themselves as using a data connection for more than an hour a day (23% use it between one and three hours, and 8% use it for more than three hours). Some 34% use the data connection between 20 minutes and an hour a day, 21% between 10 and 20 minutes a day, and perhaps most surprisingly, 14% use it less than 10 minutes a day.

T-Mobile users love their data, though: 19% use their data connection more than three hours a day, and 25% use it for between one and three hours.

What do people use their data connection for? Primarily three things: 89% go online for information such as search results, maps, weather, transit details and business ratings; 85% use it for email; and 72% use it for Web browsing.

Social networking came in a distant fourth, with 35% of people using it for that. Apart from that, no other single use -- downloading apps, streaming music or videos, shopping, using cloud storage/productivity tools, etc. -- cracked the 30% barrier.

Our survey also shows that online mobile gaming hasn't caught on with respondents: Only 7% said they use their smartphones to play games online.

Plans, contracts and costs

When it comes to contracts and plans, survey respondents are a family-oriented bunch, with 50% on family plans and 27% on individual plans.

The remainder are nearly evenly split between business plans (12%) and data-sharing plans that include other devices such as tablets (11%).

Long-term contracts, rather than month-to-month or pre-paid ones, still rule: 84% of respondents have long-term contracts, 12% are month to month and 4% are pre-paid.

And despite provider attempts to the contrary, unlimited data plans are still common: 56% of respondents are on unlimited plans, 40% are on tiered plans and 4% don't know.

Those numbers are deceiving, though, because Sprint and T-Mobile customers overwhelmingly are on unlimited plans, with about 96% of Sprint subscribers with unlimited plans (only 1% say they are on a tiered plan, and the other 3% don't know), and 73% of T-Mobile users on unlimited plans.

As for pricing, the results are divided into two groups: those who reported monthly costs for their data plan only, and those who said they use a voice + data bundle.

In the data-only group, slightly more than half -- 51% -- pay $40 or less for their monthly data service, 24% pay between $41 and $60, 11% pay between $61 and $80, 6% pay between $81 and $100, 7% pay between $101 and $150, and just 1% pay between $151 and $200 for data only.

In the voice + data bundle group, 18% pay less than $40 per month, 20% pay from $41 to $60, 15% pay from $61 to $80, $13% pay from $81 to $100, 16% pay from $101 to $150, and 9% pay from $151 to $200. At the top end of the spectrum, 9% spend more than $200 per month for a voice + data bundle.

Why people chose their mobile providers

We also asked participants on what basis they chose their carriers: price, coverage, plan options, the availability of a specific phone, or "other." We asked them to rank how important each factor was, with 1 being the most important and 5 being the least important.

Did you choose your carrier based on...

Percentage of respondents who ranked each reason 1 or 2, where 1 is most important and 5 least important

Coverage: 71%

Price: 50%

Plan options: 38%

Specific phone: 28%

Other: 16%

Source: Computerworld mobile data service survey, 2013

Base: 820 respondents

The results are clear: Network coverage was the most important factor overall, with 71% of people ranking it at either a 1 or a 2. Next was price, with 50% ranking it a 1 or 2.

Having a variety of plan options wasn't of overwhelming importance to people when they decided what carrier to choose -- only 38% gave it a 1 or a 2. The availability of a specific phone was least important overall, with only 28% rating it as a 1 or 2.

Finally, 16% of respondents chose "other" as the primary or secondary factor in their carrier decision. Common reasons they wrote in included data speed, customer service, the reputation of the provider, the fact that family members use that provider, and loyalty to the provider. Others said they use their provider because they're on a company plan or because they receive an employee discount with that provider.

We'll delve more into why people chose each of the specific carriers later in the story.

The rankings: Best and worst mobile data providers

Which providers are ranked best and which the worst among our survey takers? We crunched the numbers and came up with weighted averages on a scale of 1 to 5.

Verizon was the solid favorite -- with ratings at the top or near the top in every one of the eight individual categories, it came in first with a total weighted rating of 3.76 out of 5. At 3.71 overall, AT&T was a respectable number two, just ahead of T-Mobile with a 3.66. Sprint, meanwhile, was the clear loser at 3.42.

Verizon did particularly well in the categories grading the network's coverage and performance, receiving the highest ratings, mostly 3.8 and one 3.9, for download speed, upload speed, reliability of connection and availability of connection. AT&T came in second, with ratings of 3.6 or 3.7 for all those categories, and T-Mobile was third with ratings ranging from 3.3 to 3.8. Sprint was by far the worst performer, with the lowest rankings in every one of those categories, either a 3.1 or 3.2 for each.